If you want a workflow to check if another workflow is running you can test the the column that holds the workflow status. In the list view you will see something like: In progress, cancelled, etc. These status indicators can change depending on the language that SharePoint or Nintex is running in. So to make sure you don’t run in to language problems you can check the status based on the numerical value of the column.
|6||Failed on Start (retrying)|
These values can also be displayed by creating a view of the list that includes columns of each of the workflows and then viewing it in Edit Datasheet.